Improvement in furnaces for economizing fuel and consuming smoke



F. P. DIMPFEL. Hot-Blast Oven.

No. 1,148. Patented May 9, 1839.

AM` PHUTO-LITHO.C0.N.Y. (OSEDRNE'S PRDCLSS.)

hun STATES FREDERICK I). DIMPFEL, OF NEW YORK, N. Y.

Specification forming part of Letters Patent No. Lil-ll@g dated May 9,1839. v'

To @ZZ whom, it 11m/y concern.-

Be it known that I, FREDERICK l?. DIMPFEL, of the city of New York, inthe State of New York, have invented an improvement in the inode ofsupplying heated air to furnaces of various descriptions, by whichimprovement a great saving is effected in the quantity of fuel employed,the smoke and combustible gases which ordinarily escape combustion arewholly or in great part consumed, and the sparks given off by the fuelare arrested, and I do hereby declare that the following is a full andexact description thereof.

I intend ordinarily to employ my improved revolving fan for forcing airinto the re, for which improved fan I have applied for Letters Patent ofthe United States; but I do not intend to limit or confine myself to theuse of this particular apparatus, as the ordinary fan-wheel or othercontrivances for blowing` may be employed and adapted to the othercontrivances by which the end in view is to be attained. In my improvedmode of blowing, the ash-pit of the furnace is to be entirely closed,excepting at the opening from the fan-wheel through which the wind isadmitted and those for its passage to the fuel through the grate-bars.My blowing apparatus I intend in general to inclose in a case or box,constituting an enlargenient of the flue or passage through which thehighly-heated gaseous products of combustion are to pass from the fireon their way to the point where they pass off into the atmosphere. Bythis arrangement the atmospheric air admitted through the fan-wheel willbe heated in its passage to the fire. I intend, also, in general to makeprovision for the admission of any desired portion of the air which haspassed through the fire into the ash-pit along with the fresh air whichis forced in by the blowing apparatus. The air within the furnace is tobe retained there in astate of pressure or condensation, and to effectthis it` is necessary to prevent its free escape therefrom into thechimney or place of final exit. The method I have adopted forobstructing the draft and condensing the air is to place under theblowing apparatus or in some situation between it and the top of thechimney or the place where the gases nally escape into the atmosphere abox or case, the upper and lower sides of which are formed of stout wireor other grating, and which is to contain a quantity of smallpebble-stones or of any other suitable material, between the intersticesof which air may be made to pass. The quantity and texture of thematerial thus contained in the box must be determined by the amount ofresistance required to produce the intended pressure within the furnace.

In the accompanying drawings, Figure l rep resents the vertical sectionof a furnace and blowing apparatus, the respective parts of which are soarranged to exhibit the manner in which my improvement may be carriedinto effect.

A is the inclosed ash-pit of the furnace, of which B is thefire-chamber.

its case C C, the wind from which passes into the inclosed ash-pit at E.The fau-wheel, with its case, is represented as inclosed within a box orenlargement of the flue leading from the furnace, (marked F FQ andthrough which the gaseous products of combustion escaping from the fireare to pass.

G G is a pipe or flue leading from the furnace into the ,box F F, wherea considerable portion of its heat will necessarily be transmittedthrough the case C G of the fan-wheel to the fresh atmospheric airpassing through it. rIhe center tube or opening, II, into the fan-wheelcoincides with an opening through one side of the box F for theadmission of air to the vanes in the ordinary way.

The furnaceand blowing apparatus are represented as standing on the topof a hollow chamber, I I, there being an opening between the box orenlargement F and the chamber I I, in which is placed the box J J, whichcontains the pebble-stones or other substances intended to obstruct thedraft. At Fig. 2 this box is shown separately in perspective.

K K is a pipe or fiue leading from the chamberI I, and carrying off thegases which have passed through it.

Instead of the chamber I I and its appendages, there may bea fiue orchimney leading from the opening in which the box .I .I is representedas placed, and said box may be situated at the top or in any part ofsaid chimney, and still answer the purpose of keeping up the pressure inthe furnace, bythe aid of which time is allowed for amore perfectcombustion of the smoke and inflammable gases than would otherwise takeplace. and also for the D is a fan-wheel, which is to revolve withincommunication ofthe heat which is generated draft would be counteractedby the use of a fan-Wheel, requiring but little power to drive it. Thepressure may be preserved in the furnaceduring theperiod of supplying itwith fuel by the addition thereto of either of the Wellknown kinds offeeding apparatus Which have been used in other furnaces with a similarintention. I however have invented a new dc vice for the purpose ofarresting the entrance of Wind into the ash-pit when the furnace door isopened to supply fuel, which is as follows: In the passage leading fromthe fanwheel to the ashpit there is a valve, a, Fig. l, represented asopen. Z b is a rod or shaft, the descent of which closes the valve c bydepressing` the joint-piece n, (shown in dotted lines,) which isattached to the shaft of the valve a. At its upper end the shaft b isattached to the vibrating lever c, which also has attached to it the rodd, the lower end of which is so formed as to be latched by thespringcatch. (Shown separately in Fig. 6.) When the latch of the door israised, it strikes the piece e, disengages it from the rod d, and leavesthe rod b to descend, which it does by its own gravity, and thus closesthe valve c. By the same action a valve at fmay be opened, so as to givean escape to the draft through the pipe l(/,the rod b being connected bya jointpin with the piece o, attached to theshaft of the valve. I have,however, found the valve a sufficient for my purpose Without theaddition of that at g.

Then I wish to pass a portion of the gaseous products of combustion asecond time through the fire along with the atmospheric air supplied bythe fan-Wheels, I make an aperture through the case C C of the fan-Wheelwithin the box F F. This openingI locate so that the pressure of the airWithin the fan Wheel at the place Where it is formed shall be nearly thesame with that of the condensed air contained Within the furnace orWithin the box F F, as this air is not to enter in consequence ofanything like exhaustion being produced in the furnace,as,instead ofthis, a constant pressure is to be maintained there so long as the thefan-wheel is in action, as upon this, mainly, I am dependent for theadvantages proposed to be attained by me.

rutile Fig. 3 is a top View of the box F F, the cover of Which isremoved to show the casing of the fan-Wheel within it, which is supposedto be my improved Wheel above referred to. C C is the casing of thisWheel, and h It is the opening for the admission ofthe heated air intothe body of the wheel through the chamber formed by the neck i i, whichportion of the apparatus is shown Vseparately at Fig. 4L, which is asection of it. I regulate the size of the opening h 7L by means of asliding shutter, which may serve to close it entirely, if desired. Thisshutter is marked j j in the drawings. It is curved so as to adapt it tothe cylindrical portion of the casin g, and slides in and out through anaperture made to rcceive it.

When the common fan-Wheel is employed, I make an opening through one endof the casing which contains it, as shown at k h, Fig. 5, such openingbeing made at a point where it is judged or Where experiment may showthat the pressure of the air in the box F F will cause it to enter inproper quantity,or rather with the proper pressure, as its quantity maybe regulated by a sliding shutter or valve.

What I claim as my invention, and desire to secure by Letters Patent inthe above described apparatus, is-

l. The employment of a box or receptacle constructed in the manner setforth, and which is to contain a stratum of pebblestones, or of anyother material which will leave interstices through which air may beforced to pass, but y y y which will have the effect ofproducingpressure within the furnace applied with air from any suitable blowingapparatus, and in which furnace the air is to be forced into a closedashpit, the Whole being combined and arranged substantially in themanner set forth.

2. The mode described of forcing in with the atmospheric air a portionof that which has previously passed through the fire, by which means itis made to enter in consequence of the pressure to which it issubjected.

3. The manner of shutting off the draft from the blowing apparatus bythe opening of the door for feeding the fire, as set forth.

And I do hereby declare that I do not intend by anything hereincontained to confine myself to any particular form or arrangement of therespective parts herein described, but to vary these in any Way,substantially the same by which they will be adapted to the proposedend, as set forth in my claims.

FR. l). DIMPFEL.

"Witnesses:

Tiros. P. JoNns, Trrorras Joinvs.

